FIG. 1 depicts a conventional write head 10, which is typically incorporated into a merged head (not shown) including the conventional write head 10 and a conventional read head (not shown). The conventional write head includes a conventional first pole (P1) 20, a conventional write coil 30 insulated by insulating layer 32, a conventional write gap 40, and a conventional second pole (P2) 50. The conventional P1 20 and the conventional P2 50 are separated by the conventional write gap 40 in the region of the pole tip. The conventional P1 20 and the conventional P2 50 are typically composed of ferromagnetic materials. The write coil 30 is used to carry a coil which energizes P1 20 and P2 50 during writing. The insulating layer 32 is typically a hardbaked photoresist.
In order to improve the ability of the conventional write head 10 to write to higher density media (not shown), it is desirable for at least a portion of the conventional P1 20 and the conventional P2 50 have a high saturation magnetic flux density (Bsat) and a low coercivity. A material can be considered to have high Bsat when the Bsat is above 2 Tesla. A material can be considered to be soft, having a low coercivity, when the coercivity is less than approximately thirty Oe. To fabricate such high Bsat, soft ferromagnetic materials, the P1 20 and P2 50 are typically plated. A variety of soft ferromagnetic materials having the high Bsat have been explored for use in poles such as P1 20 and P2 50. In particular, CoFe and, to a lesser extent, CoNiFe have been investigated. Bulk CoFe has a high Bsat, values of up to 2.4 T have been reported. However, CoFe alloys may have a higher coercivity. In addition, the CoFe are subject to corrosion, which is undesirable for conventional write heads 10. Plated CoNiFe has been investigated. For example, U.S. Pat. No. 4,053,373 discusses plating of CoNiFe in a variety of solutions, including those containing hydroxymethyl-p-tolylsulfone. However, there is no indication that CoNiFe having both sufficiently high Bsat and the desired softness have been obtained.
Accordingly, what is needed is a system and method for obtaining a soft high Bsat plated material that may be suitable for use in write heads. The present invention addresses such a need.